> good idea one way or the other. Course, this meant a search of the PCP> lists or increasing the size of the PCP structure - swings and> roundabouts :/

The PCP list structure irks me a bit. Manipulating doubly linked listsmeans touching at least 3 cachelines. Is it possible to go to a simplelinked list (one cacheline to be touched)? Or an array of pointers topages instead (one cacheline may contian multiple pointers to pcp pageswhich means multiple pages could be handled with a single cacheline)?